Cushioning device



Feb. 17, 1948. G, J. CHRISTENSON 2,436,163

CUSHIONING DEVICE Filed Feb. 25, 1944 Patented Feb. 17, 194$ UNITED STATES ATENT OFFICE 2,436,163 ous monm or D vr'oE' Application February 25, 19.44, SerialNo. 523,951 a- Claim 5. (c1. 267-9) 1 This invention relates to improvements in cushioning devices and it consists of the matters hereinafter described and more particu-.. larly pointed out in the'appended claims.

One of the objects of the'invention is to providea spring and friction type of cushioningdevice which is of simple construction so as,

to be inexpensive to manufacture andwill assure a long period of trouble-free operation.

Another object of the invention is to provide a cushioning device that includes a novel friction shoe having oppositely disposed wedging surfaces and which shoes may be placed in the assembly, either end first, and may be reversed end for end to provide a new wedging surface when the one first used becomes worn in service. Also it is an object of the invention to pro vide a cushioning device of this kind so constructed as to reduce, if not entirely eliminate,

breakage of the bolt that holds the parts of the device in assembled relation.

The above mentioned objects of the invention, as well as others, together with the advantages thereof will more fully tion proceeds.

In the drawing: 1

Fig. 1 is a vertical sectional view through a cushioning device embodying the preferred'form of the invention.

i Fig. 2 is a horizontalsectional view through the same as taken on the line 2-2 of Fig. 1.

Fig. 3 is a perspective view of one of a plurality of friction shoes embodied in the improved cushioning device.

Fig. 4 is a bottom plan view of a certain collar embodied in the improved cushioning device.

Referring now in detail to that embodiment of the invention illustrated in the drawings, the improved cushioning device includes a main spring III. This spring is preferably formed from a length of square rod or bar stock, thus providing a cylinder having an external friction appear as the specificasurface interrupted only by the spacing betweenthe convolutions thereof. The endmost convolutions of the spring are ground to provide flat ends for the spring.

The flat ends of the spring l0 engage or abut against follower plates H and I2 respectively. These plates, which are counterparts, are of a diameter somewhat greater than that of the spring so that peripheral margin thereof extend outwardly from the periphery of the spring. Each plate is provided with a central hollow boss I 3 of a diameter to enter the associated with reference to said plates. Each bossin'cludes an apertured end Wall I4. A headed bolt l5 passes through said apertured end wall of each plate to receive a nut I6 and retain the parts of .the device in assembled relation. A spring l'l. surrounds that part of the bolt between its I head l8 andthe end wall I 4 of one of the plates H-l2 to absorb rebound shocks which might otherwise-fracture the retaining bolt. I T

|9-I9 indicate a plurality of arcuate or partly cylindrical: friction shoes, of a length less than' that of the spring 10 when disposed between the follower plates I l and I2. One of said shoes is "shown in perspective in Fig. 3. These shoes, which; are arranged in grouped relation about one'end ofthe spring I 0, each engages at one end with one of the p1atesll-I2. Each shoe has an internal friction surface 20 which conforms to the external friction face of the spring Hi. When said shoes are arranged in the posi-' tion they occupy in the device, they provide a split cylinder, the parts of which are capable'of a limited movement radially with respect to spring.

Each shoe 'is' provided on its external surface, midway between its ends with an outwardly projecting rib 2| having oppositely inclined wedge surfaces '22 22 respectively. With the shoes vumad'e as described,'the ends of the shoes are reend of the spring III to keep the same centered versible so that no particular care is required in arranging a particular end in'a particular position in the assembly of the device.

23 indicates a rigid collar that surrounds one end of the shoes Ill-l9 and holds them together operatively in grouped cylindrical position. This collar is provided at one end with a fiat surface 24 that forms a spring seat, as will later appear and is provided at its other end with a bevelled surface 25 of the same inclination as the surfaces 22 of the shoes.

A spring 26 is so disposed in the assembly that it engages at one end upon the seat 24 of the collar 23 and abuts at its other end against the other of the plates H-IZ. As best shown in Fig. 1, the outside diameter of the rib 2| of the I operating through the follower plates ll,

determines the amount of axial expansion of the spring It and as the limit thereoflapproaches,

the spring I! functions to cushion the action on the bolt so that shook sufficient 'to fract'ure the bolt is avoided.

Should the active surface 22 of the shoes beom rn h ou ahat wai ing qu tin i e h dev eei yte di ssmli ed and the sh e e sed n --PQii n an n in the reassembly of thedeyiceto .proyide enew actiyesurface therefor.

The .device presents no projecting external a t hi ha ca ch an we 5. 1 1??? .d e wit hi it asso iate in tor e e ema ment.

The i eof im le c s mcii ncn s s ea wes emb eend s h eieee ielaiiyel Jane e!- siye try-produce. It is positive, thoughsmootll.

inact and ih pra iisr lefi e15 n i e es While i d c b n t e evee n ,1 hav a feared in eta l to the orm er -ac me 'fiee c n ion i the p rts elcnlq est it sam is to be considered only in the illustrative sense tha I. do n i h to be =1 m ra e ere-to'es epi asma e p fic ll set i rib-i9 the ap ended claim la mm inlteni iii A u ion ng de ic tembq ng. eihe it l :8 he ica spring h n tax xternal Air-i19 face, a follower plate for each end of said s mpg,

aplurality of friction s hoesgarran ged ieggtern l'y of -said sprin an ach en a ed atone .ens av t one of said follower 1 Plates, :each shpe ,havi

internal surface for engagement withthe nal friction surface ofsaidespliing-zandfeach s oe having an externaltapered surface, and-,a sec- 0nd: spring hearing at one ;;:end :againstp the other of said follower plates and at its other end ex erting a pressure action upon said tapered surfaces of said shoes.

2. A cushioning device embodying therein a helical spring having an external friction surface, a follower plate for each end of said spring, a plurality of friction shoes arranged externally of said spring and each engaged at one end with one of said follower plates, each shoe having an internal surface for engagement withthe exterhal-f-riction -surface of said spring and each shoe having an external tapered surface, a collar sur-- rounding portions of said shoes and having a surface formed for engagement with the tapered s'urface'sof said shoes, and a second spring bear- ;ingsat onetend against the other of said follower follo'wer'plat each end of the spring, a pl1 1 llal ty of shoes eachhaving an internal surface for en g ent with the frictionsurfacehf said spring and e hilriav'i'ng'v a portionprojecting from ang atits other end bearing against said theexternallsurface thereof an formed to provide. itely .tape'rin surfaces between the .7 5 t ine i h n eid ho s may be engaged with'one of isa'idlfolloviier plates, "a collar surrounding portions of said shoes and haying eit rfengagem nt withione'fof ai argeted s iae e aMfseid shoesia a seeonjdspring liearingiat' one end .ag'ains't' the other ,of said followerplatesfland bearing iatilt's oither-end -with'saidcollar. f GUs JeQHR sI N on IP FEBENCE C TE! ZI he .:following references :are. of record .in the 

